Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bugs in the gut trigger production of important immune cells

16.10.2008
The finding may lead to new treatments for inflammatory bowel disease

A new study reveals that specific types of bacteria in the intestine trigger the generation of pro-inflammatory immune cells, a finding that could eventually lead to novel treatments for inflammatory bowel disease and other diseases.

The study by NYU Langone Medical Center researchers is published in the October 16 issue of the journal Cell Host and Microbe. The new finding adds to the growing body of research showing that the kinds of bacteria in our intestine, and in our stomach, have an impact on our health.

"There is more and more evidence that gut flora have a tremendously important influence on human health," says Yasmine Belkaid, Ph.D., chief of the mucosal immunology unit in the laboratory of parasitic diseases at the National Institutes of Health "If some set of microbes induces a specific immune response, this points to a way to manipulate the immune system," says Dr. Belkaid. "This new study is the first report that has associated a defined set of gut flora with the induction of specific immune cells."

The new research is from the laboratory of Dan Littman, M.D., Ph.D., the Helen L. and Martin S. Kimmel Professor of Molecular Immunology at NYU School of Medicine and a Howard Hughes Medical Institute Investigator. "It's not the amount of microbial flora but the kind of microbial flora that seems to count," says Dr. Littman.

The new study found that cytophaga-flavobacter-bacteroidetes (CFB) bacteria were associated with the creation of Th17 cells in mice. Typically, in both mice and humans, most of the bacteria found in the gut fall into the CFB phylum or another phylum called Firmicutes. These bacteria play many roles, such as aiding in digestion and protecting against pathogens by outcompeting harmful bacteria.

Inflammatory bowel disease (IBD) affects as many as 700,000 people each year and is one of the most prevalent gastrointestinal diseases in the United States. Treatment with antibiotics has had limited success. But pinpointing the specific species of bacteria that influence the balance of inflammatory cells, says Dr. Littman, could lead to more sophisticated treatments that fine-tune bacteria in the intestine and, in turn, dampen the production of inflammatory cells.

The Yin and Yang of Immunity

A healthy immune system is a balancing act between two opposing yet intimately connected forces, one calming, the other inflammatory. Sometimes called the yin and yang of adaptive immunity, pro-inflammatory cells (the "yang") dominate when the body needs protection, and regulatory cells (the "yin") soothe the immune system when it doesn't.

When this balance is disrupted and there is an overload of fiery yang cells, inflammatory disease results. In recent years, scientists have linked a striking number of autoimmune disorders to excess pro-inflammatory cells, including psoriasis, inflammatory bowel disease, and multiple sclerosis. "The number of inflammatory diseases known to involve T helper 17 (Th17) cells," – the fiery yang cells – "seems to be growing every week," says Dr. Littman.

For this reason, Dr. Littman has been studying the molecular pathways that stimulate the production of these cells. Recently, his team reported on a promising potential therapeutic target that may help ameliorate diseases associated with overproduction of Th17 cells.

In the new study, Dr. Littman's team observed that newborn mice that remain isolated from bacteria never generate any of these cells. Normally, newborn mice are born without any bacteria or Th17 cells in their intestines. They begin to generate the cells only after they begin to eat food and ingest bacteria. These observations suggested that the introduction of bacteria in the gut is associated with the creation of Th17 cells.

To determine if the bacteria actually cause the generation of Th17 cells, the team gave normal, bacteria-filled mice antibiotics that selectively killed some of the bacteria in their small intestine. Some of these antibiotics also depleted their Th17 cells, indicating for the first time a causal link between specific bacteria and the generation of inflammatory cells.

Littman's team then found a colony of mice that have intestinal bacteria but do not have Th17 cells. This colony, it turned out, had different bacteria in their guts than other colonies. "The same way people from different countries have different bacteria in their guts, mice from different colonies will have different bacteria," explains Dr. Ivaylo Ivanov, an author of the study and a post-doctoral fellow in Dr. Littman's laboratory. In this case, "one colony has the bacterial species associated with Th17 cells and the other doesn't."

By comparing the intestinal bacteria in mice, the team discovered that cytophaga-flavobacter-bacteroidetes (CFB) bacteria were associated with the creation of Th17 cells. Dr. Littman's team is now working to determine the specific bacteria that induce pro-inflammatory immune cells in mice. They will use this information to help determine the bacterial species in the intestines of humans that trigger the overproduction of these cells.

Dr. Littman also is interested in identifying the signals emitted by bacteria that influence the innate immune system, which responds to immediate threats from foreign pathogens and produces substances that spur naive or unspecialized T cells to develop into Th17 cells. Manipulation of the bacteria or their products, says Dr. Littman, could then be used to shift the balance of pro-inflammatory and regulatory immune cells.

Lorinda Klein | EurekAlert!
Further information:
http://www.nyumc.org

Further reports about: Bugs TH17 immune cell immune system inflammatory bowel disease

More articles from Studies and Analyses:

nachricht The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

nachricht A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>